Determination of lead and antimony in urine by atomic-absorption spectroscopy with electrothermal atomisation

Abstract

Two methods have been developed for determining antimony and lead in urine. In the first method the urine is wet oxidised and the metals are extracted as chelates into an organic phase. This is then analysed by atomicabsorption spectroscopy after carbon-rod atomisation. Nitric acid must be eliminated from the wet-oxidation mixture because it causes incomplete recovery of the antimony. In the second method the lead and antimony are extracted directly from the urine and are again determined by atomic-absorption spectroscopy with carbon-rod atomisation. This is the preferred method for the routine analysis of normal urine samples. The wet-oxidation method is used for samples that contain abnormal amounts of coproporphyrins, chelating agents or other organic materials. Both methods gave comparable results in the range 0–200 µg l^–1 of lead and antimony.